It is established practice in many large commercial laundries to use a "Central Liquid Supply System". With this system all washing chemicals such as soap, alkali, bleach, sour, softener, etc., are made up at a central location as stock solutions and are then pumped through pipes to the various washwheels, where they are measured or metered into the washing machines according to a programmed sequence.
One of the more important chemicals used in this operation is the soap. This product is purchased as a dry flake or powder and is dissolved in a tank with the aid of heat and agitation. Live steam is often used for this purpose. It is desirable to obtain as concentrated a soap solution as is feasible for a higher concentration leads to economies in time and size of the pipes and tanks.
A serious drawback to this central supply system is the tendency of the stock soap solution to gel. When gellation occurs in the stock tank it is difficult and time-consuming to bring it back to a liquid state because the stirrer usually cannot move the gelled mass while it is being heated. If gellation occurs in the pipes and conduits it is an even more difficult process to unclog and clean them. When gellation sticks valves, it throws the system completely off and this condition is still more laborious to correct.
To help overcome the tendency of the soap solution to gel, the laundry operator will use all or a combination of any of the following precautionary procedures. He will prepare a less concentrated solution, keep the solution hot at all times, have a heating system on all the conduits, have a closed loop delivery so that when the soap is not being delivered to a washwheel, it is constantly re-circulated. Despite these precautions, due to human error, or mechanical failure, gellation still occurs and is a problem in this system.
It has been suggested in the past to prepare germicidal liquid castor oil soaps which, if they become gelled or saponified, may be partially restored to the liquid state by subjection of the gel to the application of heat and free fatty acids derived from castor oil such as ricinoleic acid. However, there has not heretofore been described a soap composition in dry form which when put into solution in water at a high concentration using agitation and heat would not gel upon standing and cooling. Such a composition would be of considerable value to the laundry industry.
It is an object of the present invention, therefore, to describe a method for preparing and using such a soap composition which overcomes all the above noted deficiencies of the prior art and has new properties of stablility never before appreciated. The following description of the invention will set forth the means which must be taken to attain this object and the invention will be further illustrated by reference to a preferred mode of practice of the technique for making and using the soap composition described and claimed.